Saving energy doesn’t require sacrifice. It also doesn’t have to be complicated, thanks to occupancy and vacancy sensors and home automation systems.

Both energy-efficient and affordable, occupancy and vacancy sensors can reduce the electricity used for home lighting by as much as 30%. Occupancy sensors automatically turn lights on in response to motion—for instance, someone entering a room—and off if no motion is detected for some time. In contrast, vacancy sensors must be turned on manually but automatically turn lights off when a space is unoccupied for a specified time. Ideal for homes with pets, vacancy sensors are activated only by human occupants.

Both types of sensors use infrared technology to detect body heat and ultrasonic technology to detect movement. Some commercially available options also use photo sensors to detect daylight and keep lights off when there is sufficient natural light.

Residential sensors are available for less than $20 per switch. Installation is relatively simple, and setup involves only basic programming. Because occupancy and vacancy sensors work with many kinds of lightbulbs—incandescent, fluorescent, and LED, to name just a few—they can easily integrate into an existing home lighting system.

For those looking to save energy on a larger scale, home automation systems are a convenient way to manage home energy use. They can be controlled in the house or remotely via mobile devices and be programmed to maintain specific conditions to make energy savings even more convenient. By monitoring and displaying energy use, home automation systems can also teach homeowners about their energy habits and ways to improve efficiency.

Although a home automation system is likely to result in savings over time, it requires an initial investment of $5,000 to $15,000. This includes components such as the control box, monitor screen, individual subsystems, and computer software.

For Solar Decathlon 2013, the Southern California Institute of Architecture and California Institute of Technology team installed a house monitoring and automation system in its DALE house. These whole-house systems monitor and display energy use, which helps homeowners reduce their energy consumption. (Credit: Jason Flakes/U.S. Department of Energy Solar Decathlon)

Many U.S. Department of Energy Solar Decathlon teams have featured home automation systems in their competition houses. For example, in 2013, the Stanford University team installed a home automation system in its Start.Home. The system gathered electricity and water use data and provided continuous feedback to educate and inform the decathletes and visitors. The Solar Decathlon 2013 Southern California Institute of Architecture and California Institute of Technology team also installed a home monitoring and automation system in DALE. This system monitored energy and water consumption while collecting energy-generation data from the house’s photovoltaic array.

Irene Ying and Alexis Powers are members of the U.S. Department of Energy Solar Decathlon communications team.

David Lee works in business development at Lowe’s. He researches new opportunities and new business models that can help the company expand or reach new markets. And he landed this job, he says, thanks to the U.S. Department of Energy Solar Decathlon.

Lee was the communications manager of the Appalachian State University Solar Decathlon 2011 team, whose Solar Homestead won the People’s Choice Award. Participating in the Solar Decathlon, he says, provided him with invaluable experience and tools that resonate in the business world.

David Lee accepts the Solar Decathlon 2011 People’s Choice Award on behalf of Appalachian State University. He says the Solar Decathlon was one of the most powerful experiences of his life. (Credit: Stefano Paltera/U.S. Department of Energy Solar Decathlon)

“The process of developing a shared vision and the organizational abilities to carry out that vision are skills I developed through the Solar Decathlon that I put to use constantly in my work,” Lee says. “Additionally, during the competition, it was critical to be able to take the most complex technical specifications of home materials, systems, and technology and communicate those ideas succinctly in a way that anyone could understand.”

During the time Lee worked on the Solar Decathlon, he developed strong ties with team sponsors. Lowe’s was the team’s top sponsor and a sustaining sponsor of Solar Decathlon 2011. After that Solar Decathlon, Lee joined Lowe’s staff.

“The two and a half years I spent on the Appalachian State Solar Decathlon team formed the framework of some of the most influential experiences of my adult life. It gave me opportunities to develop a diverse array of skills, reinforced the value of hard work, facilitated deep personal and professional connections, and it directly led into a rewarding career,” Lee says.

David Lee, a Solar Decathlon 2011 alumnus from Appalachian State University, visited Solar Decathlon 2013 in Irvine, California. He says the Solar Decathlon gave him invaluable experience and skills that directly led to a rewarding career. (Credit: Carol Laurie/U.S. Department of Energy Solar Decathlon)

“The Solar Decathlon has an impact on every single person who has the chance to see a competition house. These houses show that, without a doubt, living more efficiently and independently, with a smaller environmental impact, in a net-zero-energy home is not something that requires a sacrifice of comfort or is a futuristic pipe dream,” Lee says. “Personal energy independence through affordable efficiency and solar power is a reality that is here today. Sharing that awareness with visitors to the Solar Decathlon is the biggest value that can be delivered.”

Irene Ying is a member of the U.S. Department of Energy Solar Decathlon communications team.

Temperature control, whether heating water for a bath in winter or cooling a bedroom on a blazing summer day, is essential to a comfortable home.

Heating and cooling eat up 48% of an average home’s energy bill, but you can have it all—comfort and efficiency—with heat pump systems. In contrast to conventional temperature control, which is achieved by generating heat or cold, these technologies “transfer” heat, which is far more efficient than creating it. In fact, a modern heat pump uses about 50% less electricity than a furnace or baseboard heater. In moderate climates, heat pumps can provide up to three times the energy they consume. As a bonus, in warm weather, heat pumps can do double-duty as air conditioners by moving hot air outside instead of in.

Three types of heat pumps, differentiated by heat source, are currently available: air, water, and geothermal.

A team member from the Santa Clara University Solar Decathlon 2013 team discusses the heat pump system in the team’s Radiant House. This system used hot water to heat the house and cold water to cool it. (Credit: Carol Laurie/U.S. Department of Energy Solar Decathlon)

Air-based systems generally use fans to extract heat from ambient air outside the house and then transfer the heat indoors. Air-based systems can also run in reverse, transferring indoor heat outdoors to cool the interior. Such systems are the easiest and most economical to install. However, because they rely on outside air temperature, air-source heat pumps are less efficient in climates in which temperatures dip below freezing.

Geothermal systems, which use the heat in the Earth’s crust, can reduce the energy cost of household heating by up to 60%. These systems use long loops of tubing buried in the ground to extract heat from the ground. Because the ground is warmer than air in winter, geothermal systems work more efficiently at lower temperatures than air-source systems. Likewise, the ground is cooler than the air in summer, so geothermal systems are also more efficient air-conditioning devices in hot climates. They are, however, more expensive than air-source installations.

Water-source systems transfer heat throughout a building using closed loops of water. These systems are able to simultaneously move hot and cold water to different parts of a building, depending on the needs. Thus, some parts of a building can be heated while others are cooled. For instance, the unwanted heat of a cold storage room could be used to heat a tank of hot water for washing. In addition, if the water heater is located in the basement, it can extract moisture from the air and act as a dehumidifier in wet summer months. This option can reduce water heating costs by up to 50%. However, this technology can require more extensive work to install.

Air isn’t the only thing that can be efficiently heated by heat exchange; water can also be heated using a heat pump water heater. Similar to the water-source heat pump, heat pump water heater systems work by drawing heat from the surroundings—for example, outdoor air in the summer and the warm ground in the winter—but use the energy to heat water instead of air. Compared to conventional water heaters, heat pump water heaters are up to three times more energy-efficient.

Many U.S. Department of Energy Solar Decathlon teams have used heat pumps to achieve energy-efficient competition houses. In 2013, the University of North Carolina at Charlotte used a pump system with both heating and cooling capabilities, plus a system of capillary cubes circulating water, to achieve cooling without using compressors or refrigerants in the UrbanEden house. The University of Nevada Las Vegas team likewise used pump systems for heating and cooling its DesertSol, which was designed for the extreme conditions of desert living. Radiant House, from Santa Clara University, created a uniform living environment using a water-based heat pump system.

As the Solar Decathlon continues to demonstrate, amenities such as hot showers and air conditioning need not be sacrificed when constructing or living in an energy-efficient home.

Learn more about the benefits of the various types of heat pumps at the Energy Savers website.

Irene Ying is a member of the U.S. Department of Energy Solar Decathlon communications team.

As a project coordinator for building management software company Lucid Design Group, Cordelia Newbury works with customers to reduce their energy use. And although she now coordinates the energy efficiency of tens of buildings at a time, her career in energy-efficient spaces began with one-house projects—on Middlebury College’s U.S. Department of Energy Solar Decathlon 2011 and Solar Decathlon 2013 teams.

“After working on the construction of the Self-Reliance house for Solar Decathlon 2011, I became more curious about architecture and building efficiency movements and was hooked,” Newbury explains. “So I incorporated building efficiency into my academic work and continued on with Solar Decathlon 2013.”

Newbury served as team manager of Middlebury’s InSite house for Solar Decathlon 2013. She describes her role as “acting as a central resource for the team to connect students with each other and with external resources such as contractors to keep us on track.” This meant that she did a little bit of everything: from buying groceries and acting as travel agent for 70 team members to performing late-night construction, hosting fundraising meetings, and coordinating design teams.

Cordelia Newbury, second from left, shares a light moment with Middlebury College Solar Decathlon 2013 teammates (from left) Ari Lattanzi, Marcel Rodgers, and Jack Kerby-Miller. Newbury credits her Solar Decathlon experience with helping her become an energy-efficiency project coordinator for a building management software company. (Photo courtesy of Cordelia Newbury.)

Newbury didn’t just learn skills by working on the Solar Decathlon team; she also gained professional connections through her experience. During the two-year Solar Decathlon 2013 project, the team had extensive contact with administrative departments at Middlebury as well as local professionals who consulted on InSite. To Newbury and her team, these contacts were more than donors and extra pairs of hands. They also became mentors, friends, and eventually a professional network.

“The amount of responsibility that we had on Solar Decathlon is not often available through internships, and having administrators and contractors get to know me and my teammates created strong relationships that guided me to my job with Lucid,” she says.

Cordelia Newbury, who served as Middlebury College’s Solar Decathlon 2013 team manager, says the Solar Decathlon provides visitors an opportunity to interact with environmentally responsive architecture and think about how they can contribute to more sustainable spaces and lifestyles. (Photo courtesy of Cordelia Newbury.)

But most important of all, Newbury says, she found a new way of thinking about sustainable spaces and lifestyles, which drives her career today. The Solar Decathlon, she says, taught her that it’s possible to create attractive spaces that integrate sustainable building into everyday life without sacrificing comfort or beauty.

“The Solar Decathlon is on the one hand a platform to exhibit energy-efficient houses, but it is also an opportunity to spread powerful ideas to architects, builders, engineers, students, adults, or anyone who sees themselves occupying a constructed space,” she says. “I don’t think that anyone could leave Decathlete Way without remembering at least one idea that he or she could use to work toward a more sustainable lifestyle.”

Irene Ying is a member of the U.S. Department of Energy Solar Decathlon communications team.

On Aug. 28, U.S. Senate Majority Leader Harry Reid visited DesertSol—the University of Nevada Las Vegas (UNLV) house that won second place overall in the U.S. Department of Energy Solar Decathlon 2013. Now located permanently at the Springs Preserve in central Las Vegas, Nevada, DesertSol has been one of the Preserve’s most popular attractions since it opened to the public in March 2014.

Senator Reid joined former UNLV decathletes for a tour of the house led by Alexia Chen. After the tour, the senator talked on the front patio with Solar Decathlon alumni about sustainability and what they have been doing since the competition.

U.S. Senate Majority Leader Harry Reid joins former UNLV decathletes for a tour of DesertSol, the house that won second place overall in Solar Decathlon 2013. Included here are Solar Decathlon Director Richard King (second from left), Alexia Chen (fourth from left), and Senator Reid (center). (Credit: FFW Public Relations and Government Affairs)

“Everyone had a good time at this event—especially the decathletes, who were still marveling at the house they built and how it continues to teach the public. Several of the former UNLV students raved to me about what a beneficial learning experience the Solar Decathlon was for them,” said Richard King, Solar Decathlon director. “The senator’s visit was a proud moment for the students, the university, and the Springs Preserve.”

DesertSol is now a permanent exhibit in the Springs Preserve Botanical Gardens, where visitors can tour the house and learn more about its features. The University of Nevada Las Vegas designed the house to reflect the spirit of the Mojave Desert. With reverence to the sun as both a source of harsh conditions and a solution for sustainable living, DesertSol harnesses abundant sunlight for solar electricity while capturing rain to provide evaporative cooling and irrigation.

DesertSol is one of the most popular attractions at the Springs Preserve, a cultural site in Las Vegas, Nevada. (Photo courtesy Springs Preserve)

The Springs Preserve, which was listed on the National Register of Historic Places in 1978, is a 180-acre cultural institution designed to commemorate Las Vegas’ dynamic history and provide a vision for a sustainable future. The Springs Preserve features museums, galleries, outdoor events, colorful botanical gardens that include DesertSol, and an interpretive trail system through a scenic wetland habitat. Pardee Homes, one of the sponsors of DesertSol, helped the team prepare the site and rebuild the house at its permanent Springs Preserve location.

Carol Laurie is the communications manager of the U.S. Department of Energy Solar Decathlon.